According to a new study, if you’re looking to make an app that’s profitable, make it freemium. In seven of the Apple App Store’s ten largest categories, the majority of revenue comes from in-app purchases. It’s not necessarily the most groundbreaking announcement, but it’s another important reminder that in-app purchases are more important, from a revenue standpoint, than the app itself, in some ways. While developing an app, or looking to come up with advertising strategies for apps, this concept is crucial to integrate.